Highly-concentrated stable solutions of sulphurous acid and method of producing it



Patented June 24, 1924.

PATENT -FFHCE.

EMANUEL FELHEIM, OF BERLIN-LICHTENRADE, GERMANY.

HIGHLY-CONCENTRATED STABLE SOLUTIONS OF SULPHU'ROUS ACID AND METHOD OFPRODUCING IT.

No Drawing.

To all whom it may concern Be it known that I, EMANUEL FELHEIM residingat Berlin-Lichtenrade, Germany,

have invented certain new and useful Improvements inHighly-Concentrated1Stable Solutions of Sulphurous Acid and Methods ofProducing It, of which the following is a specification. 1

My invention relates to sulphurous acid solutions and an improved methodof pr oducing a highly concentrated solution of sulphurous acid whichwill not decompose or be liable to any reduction as regards itsefiiciency, for a very long time.

Sulphurous acid has been suggested heretofore as a reliable means forkilling or exterminating vermins particularly bugs, bedebugs, lice,flour-moths, scabmites and the like, but the acid has heretofore usuallybeen employed in practice in a gaseous state.

Such practice is objectionable for the reason that extremely largequantities of the gas are required in each case since in order toensure" the desired result, comparatively large rooms must be filledwith the sulphurous acid gas.

The object of my invention is to remedy this defect and with this objectin view I prepare a solution or li nor the main and eflicientconstituent of w ich is sulphurous acid, and which enables one to bringabout and maintain in the closest vicinity of the single vermin a zoneof sulphurous acid gas of sufliciently high concentration to -produce aparasiticidal eflect, without thereby filling the adjacent room with thegas as heretofore practiced.

,According to my inventlon the method of producing the saidparasiticidal solution or 40 liquor consistsin making a mixtureof anacid or acids; or of acid-salts of such acids, and a salt or saltsadapted to decomposeand develop or yield free sulphurous acid, and addinto said mixture a viscous substance 15 of suitable nature.

viscous substance ensures va double eflect in asmuch as, first, the acidor acids or acid salts (hereinafter referredto enerically as acidsubstances) are there y prevented The addition of said- Applicationfiled February 12,1924. Serial N0. 692,425.

from reacting too violently with the sulphurous salt or salts, or inother words, the reaction and development of free sulphurous acid isretarded, and second, the developed sulphurous acid gas is prevented bythe viscous substance present from escaping too quickly into the openair.

In carrying out my invention practically I m1x a highly concentratedsolution of potassium bisulfite or of sodium bisulfite with a highlyconcentrated solution of potassium bisulfate or sodium bisulfate andaccording to a preferred example, I'add to the thus obtained mixture aviscous substance or liquor such as e. g. a highly concentrated solutionof potassium lactate or sodium lactate. i

In lieu of the hereinbefore mentioned potassium bi'sulfate and sodiumbisulfate a viscous acid such as lactic acid may be employed. i

It will be evident that my invention, whilst still being adhered to inits main essentials, may be varied and adapted in many ways, accordingto various requirements desired or most suitable under differentcircumstances.

What I claim is 2- 1. As a new composition of matter, a mixturecomprising an acid substance, a sulfite adapted to react therewith, anda substance so giving a high degree of viscosity, in amount capable ofpreventing rapid escape of the sulphurous anhydrid into the atmosphere.

' 2. As a new composition of matter, adapted to slowly'liberate $0,, amixture containing a sulfite'compound and an acid material, capable ofreacting withsuch sulfite com-- pound, which acid material is present inamount capable of giving a high, degree of viscosity, capable ofpreventing rapid escape of sulfur dioxide into the atmosphere.

3. A method of making a highly concentrated lasting solution ofsulphurous acid, adaptedfor use in exterminating vermin, which comprisesmixing together an acid isubstance, a sulfite compound adapted todevelop sulphurous acid on contact withthe said acid substance, in thepresence of water,

and a Substance giving a high degree of vistherewith, such compositionincluding a subcosity to the solution, in amount capable of stancecontaining the lactic acid radical in 10 preventing rapid escape ofsulfur dioxide amount suflicient to prevent rapid escape of into theatmosphere. the S0 into the atmosphere;

4. As a newcomposition of matter, adapt- In testimony whereof I havesigned my ed to slowly liberate sulfur dioxide, a mix name to thisspecification. ture containing a sulfite compound, together with an acidmaterial, adapted to react DR. EMANUEL FELHEIM.

